Structures, including residential, commercial and industrial buildings, are made from masonry using individual masonry blocks laid and bound together by mortar. The common materials of masonry construction are clay brick masonry; stone, such as marble, granite, travertine, and limestone; and concrete block, including without limitation conventional concrete masonry units and autoclaved aerated concrete blocks. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the blocks are assembled can significantly affect the durability of the overall masonry construction.
Concrete masonry is a commonly used building material composed of individual blocks whose basic composition is concrete. The blocks can be hollow or solid. Concrete is strong in compression and weak in tension. For concrete that is cast at the building site, adding embedded reinforcement during pouring can provide tensile capacity. Reinforcement is not used in individual concrete masonry blocks, but masonry blocks constructed of hollow units require code-required reinforcement at the build site to comply with building codes, and therefore receive the reinforcement at the build site as pluralities of blocks are mortared into units.
Masonry grout is similar to concrete and is poured into the hollow concrete masonry units at the build site to hold the code-required reinforcement, both vertically and in horizontal channels of bond beam block. Concrete, concrete masonry blocks, mortar, and masonry grout all contain Portland cement. Care needs to be taken to properly cure the grout and achieve the required strength. However, proper curing can be a challenge as typical build sites are outdoor areas subjected to environmental conditions that are different depending on the location and time of year.
Currently, individual masonry blocks are transported to the build site where they are laid and mortared into courses or rows, with code-required reinforcement installed as and after the courses are laid. To build a structure over about five feet in height, scaffolding is usually necessary to support the masons while they work. Weather can affect the progress of the masonry when laid on site as well.